Ankara sent Thursday a diplomatic note to Damascus over alleged military cargo it confiscated from a Syrian plane it had intercepted the day before on suspicions of illegal materials on board, Anatolia news agency reported.

The note was delivered to the Syrian consulate in Istanbul, on the grounds that the Syrian airliner was carrying illegal cargo in breach of the rules of civil aviation, the agency said, citing foreign ministry sources.

Turkey scrambled Wednesday two F16 jets to force the Syrian A320 Airbus flying from Moscow to Damascus to land at Ankara's Esenboga Airport for security checks into its load, after receiving intelligence that the plane was carrying weapons and ammunition headed for Syria.

Turkish Foreign Minister Ahmet Davutoglu said Ankara seized "objectionable" cargo found aboard the plane, but allowed the aircraft to take off with all of its passengers, 17 of them Russian nationals, after a nine-hour delay.

Investigation of the confiscated cargo was ongoing, as some parts were undergoing lab research, the NTV news channel reported, citing customs ministry officials.

The lengthy lab process points to the possibility that the cargo may contain materials that can be used in the making of bombs, NTV added.

Final results were expected to be received later Thursday, according to NTV